How tunnelling titanium turns a perfect crystal into a bad heat conductor
Quantum tunnelling is key to solving the mystery of why some defect-free crystals have such low thermal conductivities
The decades-old mystery of why some perfect single crystals show much lower thermal conductivities than would be expected of such materials may have been solved. A study on the perovskite barium titanium sulfide has shown that instead of being fixed in the crystal lattice, the titanium atoms constantly tunnel between positions, disrupting the flow of heat. The findings could aid the design of thermoelectric materials.